Integrated coal conversion process

Abstract

An integrated process for the conversion of coal to liquid and gaseous fuels is disclosed. Coal and oil are hydrocracked in the presence of a particulate mixture of sand or clay and an iron and chromium alloy to form carbon-coated sand and an overhead product comprising cracked oil vapors and fuel gases. The carbon is removed from the sand to form carbon monoxide with the concomitant generation of heat. The carbon monoxide is used to reduce oxidized iron and chromium alloy located in a hydrogen generating bed. Steam is passed into the bed of reduced metallic alloy to form hydrogen for use in the coal reactor and the regenerated particulate mixture of sand and iron and chromium alloy is returned to the coal reactor to continue the sequence of carbon removal and to provide heat for the hydrocracking reaction.

What I claim is: 
     
       1. A method of converting coal to liquid and gaseous fuels which comprises: (a) hydrocracking a coal and oil mixture in a coal reactor in the presence of hydrogen produced in the manner hereinafter specified in step (d) and also in the presence of a particulate mixture of sand, clay or mixtures thereof and a first iron and chromium alloy, thereby forming a spent particulate mixture of sand, clay or a mixture thereof having a carboncoating thereon and a first spent iron and chromium alloy, coal ash and an overhead product comprising cracked oil vapors and fuel gases;   (b) withdrawing the spent particulate mixture of carboncoated sand, clay or mixtures thereof and said first spent iron and chromium alloy from said coal reactor and removing the carbon coating from said sand, clay or mixtures thereof in the presence of an oxygen-containing gas to form carbon monoxide and a regenerated particulate mixture of sand, clay or mixtures thereof and a first regenerated iron and chromium alloy;   (c) passing said carbon monoxide into a bed comprising a particulate oxidized second iron and chromium alloy and reducing said particulate oxidized second alloy to metallic form;   (d) passing steam into the bed of metallic alloy obtained in step (c) to form hydrogen;   (e) passing at least a portion of the hydrogen produced in step (d) into the coal reactor of step (a) as hydrogen for effecting hydrocracking therein; and,   (f) passing said regenerated particulate mixture of said sand, clay or mixture thereof and first iron and chromium alloy from step (b) into the coal reactor of step (a) as the mixture of sand and first iron and chromium alloy therein.   
     
     
       2. The method of claim 1 further characterized in that each of the first and second iron and chromium alloy comprises from about 5% to about 30% chromium. 
     
     
       3. The process of claim 2 further characterized in that the particulate mixture of sand, clay or mixtures thereof and first iron and chromium alloy contains about 10% by weight alloy. 
     
     
       4. The process of claim 1, further characterized in that an excess of steam is introduced into the particulate second iron and chromium alloy to form a product stream comprising hydrogen and excess steam, said product stream being thereafter introduced into the coal reactor to provide at least a portion of the hydrogen requirement of the coal reactor. 
     
     
       5. The process of claim 4, further characterized in that the particulate bed of iron and chromium alloy in step (d) is a fixed bed. 
     
     
       6. The method of claim 1, further characterized in that the spent particulate mixture of sand, clay or mixtures thereof having a coating of carbon thereon and first iron and chromium alloy is oxidized in a fluidized bed to form carbon monoxide, the latter is passed upwardly into a fixed bed of oxidized second iron and chromium alloy to reduce said alloy to metallic form, steam is passed downwardly through the resultant reduced second iron and chromium alloy to form a product gas containing hydrogen, and the product gas is thereafter introduced into the coal reactor to provide hydrogen for effecting hydrocracking therein. 
     
     
       7. The process of claim 6, further characterized in that an excess of steam is passed downwardly through the reduced second iron and chromium alloy to form a product gas containing hydrogen and excess steam, and said product gas is thereafter introduced directly to the coal reactor to provide at least a portion of the steam and hydrogen requirements therefor.